522 BULLETIN OF THE BUREAU OF FISHERIES. 



Cryptonemia crenulata J. Agardh. PI. CXIII, fig. 3. 



Cryptonemia crenulata. J. Agardh, 1847, p. u. 

 Cryptonemia crenulata, Harvey. 1853, p. 184. 

 Acrodiscus 9 crenulatus, De Toni. 1905, p. 1599. 

 A. A. B. Ex. No. 23. 

 P. B.-A. Nos. S49. aioo. 



Frond flattened, mffled, 2 to 14 cm. tall, 0.5 to 5 cm. wide, supported on a short stipe, which soon 

 passes over into the expanded portion of the thallus, branching dichotomous or almost palmatifid, often 

 with similar expanded, dichotomous proliferations from the margins, margin sometimes entire, usually 

 eroso-denticulate and slightly curled, segments linear or wedge-shaped, rounded, obtuse, or truncate at 

 the apices; tetrasporangia occurring in rounded sori near the margins of the segments; cystocarps 

 appearing as minute dots, scarcely visible to the naked eye, clustered here and there on the surface of 

 the frond; texture membranaceous, rigid; color rosy purple, sometimes slightly greenish. 



North Carolina to Brazil. 



Occasional on Bogue Beach, Beaufort, N. C., August to October, sometimes bearing cystocarps. 



This species was removed from the present genus by De Toni and doubtfully placed under Acro- 

 discus Zanard. with the note that, according to the suggestion of Schmitz, the latter genus should be 

 united with Polyopes J. Ag. The structure of the cortex of this species is, however, parenchymatous, 

 agreeing with that of Cryptonemia lomation (Bertol.) J. Ag., the type of the genus, and is not composed 

 of anticlinal rows of cells, as in Acrodiscus and Polyopes. The species is accordingly retained under 

 Cryptonemia. 



This species is easily recognized by the crisp, ruffled frond, which is so rigid that it can be made 

 to lie flat only by considerable pressure. Dried specimens, when moistened, show this character almost 

 as clearly as do living plants. 



This is the northern known limit of the species and of the genus. 



Family 2. CORALLINACE/E (Gray) Harvey. 



Frond extremely various inform, filamentous, foliaceous, crustaceous, flattened, terete 

 or irregular, simple or dichotomously, laterally or irregularly branched in various ways, 

 sometimes endophytic, nearly always more or less strongly incrusted with lime, structure 

 cellular-filamentous, nearly always compact; tetrasporangia (or sometimes disporangia) 

 occurring in more or less well-defined sori embedded in the thallus, sometimes in definite, 

 flask-shaped conceptacles scattered over the frond or borne in special, swollen portions, 

 often mingled with sterile paraph.yses, usually zonately divided, sometimes forming only 

 two spores, communicating with the exterior by one or more pores;' an theridia borne in 

 flask-shaped conceptacles formed in the thallus and communicating with the exterior 

 by a pore, scattered over the frond or borne in special swollen portions, forming sper- 

 matangia singly on long stalks or in chains, mingled with paraphyses; carpogonia and 

 auxiliary cells numerous, usually borne together on upright, branched filaments arising^ 

 from the base of flask -shaped conceptacles formed in the thallus and communicating 

 with the exterior by a pore, scattered over the frond or borne in special swollen portions, 

 gonimoblasts numerous, usually arising as single cells from the periphery of a large 

 discoid cell in the base of the conceptacle, formed by the fusion, after fertilization, of all 

 the auxiliary cells, cutting off chains of carpospores in basipetal succession, the numerous 

 carpospores and parphyses finally filling the conceptacle. 



Nearly 400 species, widely distributed, mostly in warm seas. 



KEY TO GENERA. 



a. Thallus consisting of a flat disk b. 



b. Thallus, thin, composed of a single undifferentiated layer i . Melobesia (p. 523). 



bb. Thallus thick, composed of a thin lower layer and a thicker upper layer, tetra- 

 sporangia borne on the sides of the conceptacle 2. Dermatolithon (p. 524). 



